hugo/tpl/os/os.go
Bjørn Erik Pedersen 08fdca9d93 Add Markdown diagrams and render hooks for code blocks
You can now create custom hook templates for code blocks, either one for all (`render-codeblock.html`) or for a given code language (e.g. `render-codeblock-go.html`).

We also used this new hook to add support for diagrams in Hugo:

* Goat (Go ASCII Tool) is built-in and enabled by default; just create a fenced code block with the language `goat` and start draw your Ascii diagrams.
* Another popular alternative for diagrams in Markdown, Mermaid (supported by GitHub), can also be implemented with a simple template. See the Hugo documentation for more information.

Updates #7765
Closes #9538
Fixes #9553
Fixes #8520
Fixes #6702
Fixes #9558
2022-02-24 18:59:50 +01:00

143 lines
3.6 KiB
Go

// Copyright 2017 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package os provides template functions for interacting with the operating
// system.
package os
import (
"errors"
"fmt"
_os "os"
"path/filepath"
"github.com/gohugoio/hugo/deps"
"github.com/spf13/afero"
"github.com/spf13/cast"
)
// New returns a new instance of the os-namespaced template functions.
func New(d *deps.Deps) *Namespace {
return &Namespace{
readFileFs: afero.NewReadOnlyFs(afero.NewCopyOnWriteFs(d.PathSpec.BaseFs.Content.Fs, d.PathSpec.BaseFs.Work)),
workFs: d.PathSpec.BaseFs.Work,
deps: d,
}
}
// Namespace provides template functions for the "os" namespace.
type Namespace struct {
readFileFs afero.Fs
workFs afero.Fs
deps *deps.Deps
}
// Getenv retrieves the value of the environment variable named by the key.
// It returns the value, which will be empty if the variable is not present.
func (ns *Namespace) Getenv(key interface{}) (string, error) {
skey, err := cast.ToStringE(key)
if err != nil {
return "", nil
}
if err = ns.deps.ExecHelper.Sec().CheckAllowedGetEnv(skey); err != nil {
return "", err
}
return _os.Getenv(skey), nil
}
// readFile reads the file named by filename in the given filesystem
// and returns the contents as a string.
func readFile(fs afero.Fs, filename string) (string, error) {
filename = filepath.Clean(filename)
if filename == "" || filename == "." || filename == string(_os.PathSeparator) {
return "", errors.New("invalid filename")
}
b, err := afero.ReadFile(fs, filename)
if err != nil {
return "", err
}
return string(b), nil
}
// ReadFile reads the file named by filename relative to the configured WorkingDir.
// It returns the contents as a string.
// There is an upper size limit set at 1 megabytes.
func (ns *Namespace) ReadFile(i interface{}) (string, error) {
s, err := cast.ToStringE(i)
if err != nil {
return "", err
}
if ns.deps.PathSpec != nil {
s = ns.deps.PathSpec.RelPathify(s)
}
return readFile(ns.readFileFs, s)
}
// ReadDir lists the directory contents relative to the configured WorkingDir.
func (ns *Namespace) ReadDir(i interface{}) ([]_os.FileInfo, error) {
path, err := cast.ToStringE(i)
if err != nil {
return nil, err
}
list, err := afero.ReadDir(ns.workFs, path)
if err != nil {
return nil, fmt.Errorf("failed to read directory %q: %s", path, err)
}
return list, nil
}
// FileExists checks whether a file exists under the given path.
func (ns *Namespace) FileExists(i interface{}) (bool, error) {
path, err := cast.ToStringE(i)
if err != nil {
return false, err
}
if path == "" {
return false, errors.New("fileExists needs a path to a file")
}
status, err := afero.Exists(ns.readFileFs, path)
if err != nil {
return false, err
}
return status, nil
}
// Stat returns the os.FileInfo structure describing file.
func (ns *Namespace) Stat(i interface{}) (_os.FileInfo, error) {
path, err := cast.ToStringE(i)
if err != nil {
return nil, err
}
if path == "" {
return nil, errors.New("fileStat needs a path to a file")
}
r, err := ns.readFileFs.Stat(path)
if err != nil {
return nil, err
}
return r, nil
}